Here is my weekend experience with my MSD Blaster 40K coil. I've had a high speed miss for a good length of time. Around 5K RPMs in my 4.2L E Type and the car would kinda miss or not be as excited as I wanted it to be. I changed fuel pumps, fuel filters, new NGK Iridium plugs, new MSD 8.5mm wires, had the timing checked to no avile. This week the + lead from the coil came out off the slip on spade connector. I replaced the wire on the road good enough to get home. I later took the time to replace both spade connectors on each of the coils + & - lugs. I decided to wire wrap the new spades with copper wire onto the coil lugs to prevent them from coming off, even though this was not the orginal problem, the + wire came out of the spade connector. After this repair the engine ran a lot smoother, more power and no high speed miss or lack of high speed power. Every thing on the engine power curve improved. I can only think that the + wire was working its way out of the spade connector and not making as good of contact as it now is. So, if you are having some kind of engine problem, do yourself a favour and check out the little things as well as other items that need attention. Cracked vacumn lines will be your worst headache.
KoolKat in Phoenix